Indicating device



April 1961 DE WlTT T. VAN ALEN 2,979,258

INDICATING DEVICE Filed July 20. 1955 IN VEN TOR.

AMAHQJUW United States v Patent '0 i IINDICATING mzvrcn v Filed July 20,1955, Ser. No. 523,218

3 Claims. (Cl. 235- 103) This invention relates to an indicating devicewhich is direct reading.

The device of the present invention includes a multiwheel direct readingcounter and a knob adapted to control the rotation of a shaft, such asthe shaft of the potentiometer shown in my prior Patent No. 2,665,355,although the dial is adapted for connection to a variety of rotarydevices. In the device of the present invention the knob transmitsrotary motion both to the controlled shaft and to the counting wheelswhich register the extent through which the shaft has rotated.

The invention resides in my novel means for mounting the counting wheelcapsule from a panel surface, such mounting being independent of themotion transmitting connections between the device knob and the shaft ofthe controlled device with which the knob is coaxial. Accordingly, mydevice is readily applied to the projecting shafts of otentiometers,etc., there being no need to support the device on the shaft.

In the foregoing respect my device is unlike prior art direct readingdials known to me in which the counting capsule is fixedly mounted to afixed projecting stem, motion from the knob being communicated to thecontrolled device via auxiliary means.

The device of my invention is dustproof and is provided with a brake tohold the controlled shaft positively in any position of adjustment. Thebrake is specifically constructed to apply braking pressure withoutdeveloping any rotary pressure on the shaft. Accordingly, the shaftadjustment is not changed in the course of setting the brake.

In the drawings:

Fig. 1 is a perspective view of a direct reading device embodying myinvention.

Fig. 2 is a vertical cross section, partly in elevation, taken throughthe device of Fig. 1.

Fig. 3 is a disassembled elevation of the brake shoe retaining ring, abrake surface portion of the knob rotor being shown in cross section.

Fig. 4 is a view similar to Fig. 3 showing the brake shoes in releasedposition.

Figs. 5 and 6 are right and left hand views respectively of the deviceopened up to expose details, parts of Fig. 5 being shown in crosssection and other parts being broken away.

The potentiometer 10 or similar controlled rotary device may be mountedon a panel 11 with its operating shaft 12 extending forwardly therefrom.The nut 9 clamps the threaded potentiometer sleeve 8 to the panel formounting purposes. The knob 29 of the direct reading device of thepresent inveniton is connected directly to the operating shaft 12, thecounting capsule 13 of my device being supported on the panel 11 andindependently of shaft 12.

The counting capsule 13 is conventional and may comprise multiplecounter wheels 14 which rotate on the axis of mounting shaft 15 whichhas bearings in suitable sockets in the capsule housing 16. The capsuleis 2,979,258 Patented Apr. 11, v1961 provided with the usual gearing toactuate the wheels, and has a cover 17 with windows 18 through which thenumbered counting Wheels are visible. The capsule housing 16 is fixedlysupported on legs 19 which merge with a mounting ring 20 releasablysecured by bolts 23 to the peripheral flange 24 of a mounting plate 25.The mounting plate 25 is fixedly secured to panel 11 by the clampingpressure of nut 9. Accordingly, the counting capsule 13 is rigidlysupported on its legs 19 from the panel 11 and is non-rotatable withrespect thereto.

Within the legs 19, and mounted by set screw 27 to the shaft 12, is ahollow dial rotor 28 having an outer knob surface 29 exposed for fingermanipulation except where covered by the legs 19. The knob 29 is hollowto receive motion transmitting gearing hereafter described.

The dial rotor 28 is provided with a crown or ring gear 32 with whichpinion 33 meshes. Pinion 33 is free to turn on stub shaft 34 extendingradially from the hub 35 of the counting capsule housing. Pinion 33carries a gear 36 which meshes with the input gear 37 of the countingwheel mechanism.

Accordingly, if the knob 29 is rotated the crown gear 32 will rotatepinion 33 about the axis of shaft 34. This rotative movement will becommunicated by gear 36 to the input gear 37 of the counting capsule torotate the counting wheels 14 in the conventional manner.

The hollow knob 29 and capsule housing 16 interfit with reasonably closetolerance, an elastic dust seal 38 being mounted therebetween to excludedust from entering the gearing and other moving parts.

From the foregoing it is clear that the device ofthe present inventionis characterized by its novel structure in which the counting capsule 13is supported on panel 11 by legs 19 which are radially outwardly offsetfrom the knob 29. This construction permits direct connection betweenthe shaft 12 and the knob 29 which are free to rotate within the embraceof legs 19 and substantially eliminates backlash between the knob andshaft.

The rotor 28 is provided with an annular braking surface 41 which isradially inwardly adjacent brake shoes 44 mounted on spring arms 42. Thespring arms 42 are connected by rivets 40 to the flange 24 of themounting ring 25. The ends of the spring arms 42 are turned at 43 anddesirably integrally bonded to the brake shoes 44 which are desirablymade of Neoprene rub ber.

Rotatively mounted on the central flange 45 of the plate 25 is anannular cam ring 46 having a handle 47 which extends through a slot 48in flange 24. The cam ring 46 is provided with projecting cam lugs 51.R0- tative movement of the cam ring in a clockwise direction, as shownin Fig. 4, will move the lugs 51 against the spring arms 42 to cam thebrake shoes 44 radially inwardly against the braking surface 41 formedon the dial rotor 28. Accordingly, the knob and shaft can be locked inany adjusted position.

I desirably provide three brake shoes 44 in order to equalize thepressure thereof in positive bearing engagement with the brake surface41. The geometry of the braking device is such that spring arms 42 areat right angles to radii passing through the brake shoes 44 when theshoes engage the braking surface 41. Accordingly, the movement of thebrake shoes 44 toward pressure engagement with the braking surface 41 isentirely radial and there is no tangential or other non-radial componentof force tending to oscillate the knob on its axis of rotation. For thisreason the dial may be locked without danger of even the slightestchange in reading attributed to actuation of the braking mechanism.

I claim:

1. An indicating device adapted to be mounted on a panel and connectedto the shaft of a rotary instrument,

said device comprising a mounting plate, means for fastening said plateto the panel, at least one leg extending from the margin of said plate,a counter having at least one numbered element mounted on said leg, ahollow knob surrounding the shaft and ofiset radially within said legfor relative rotation of the knob with respect to the leg, meansdirectly connecting said knob to the shaft and motion transmittinggearing within said knob interconnecting the knob and numbered elementfor rotation of said numbered element on rotation of the knob.

2. The device of claim 1 in which said knob is pro vided with a brakingsurface, in further combination With a brake and means for selectivelyapplying said brake to said surface and releasing said brake from saidsurface.

3. The device of claim 2 in which said brake comprises a plurality ofbrake shoes and arms on which said shoes are radially movable withrespect to said braking surface, said means comprising a cam ring andcam lugs mounted thereon, said ring being mounted for rotation on a pathof engagement of said cam lugs against said brake References Cited inthe file of this patent UNITED STATES PATENTS 2,119,576 Goldstine June7, 1938 2,532,970 Van ,Dyke Dec. 5, 1950 2,685,944 Faucher et al. Aug.10, 1954 2,777,637 Matthew Jan. 15, 1957

